The Samsung Galaxy Note 7 fiasco remains a mystery but we’re expecting the South Korean tech giant to release the results of investigations this December. We have no idea when exactly but we can expect before 2016 ends, Samsung will end with a note about its problematic Note. It’s been a crazy four months for the company who started to get excited about the premium flagship only to be disappointed after receiving news of explosions and units catching fire.

Samsung first said it was a battery problem and so it changed supplier. Unfortunately, the same problems were reported, leading the company to announce a recall and then eventually discontinue production. Mobile revenue went down a bit but good thing, Samsung’s other businesses are doing well. We’ve noticed too that Samsung has been more aggressive in marketing and making innovations the past few months. That’s normal for a big brand who wants to keep its status especially in the mobile industry.

The past weeks, Samsung has been wooing Note 7 owners with tempting Galaxy S8 upgrade program aside from the cash discounts. But what really caused the explosions? Many people are already saying it’s the battery. Samsung Mobile’s president vowed to find the cause and we’re really looking forward to the official investigation results.

Samsung America COO issued an explanation earlier and apologized for the battery problem. The company also said production flaw caused the explosion but failed to identify what was it exactly.

It’s not really the battery but the internal design margin is too small. The result is that the battery has no room to swell up. This means battery is compressed during normal usage which is dangerous so overtime, when the battery expands, it reaches a “ceiling”.

Read the short explanation below by Instrumental:

When batteries are charged and discharged, chemical processes cause the lithium to migrate and the battery will mechanically swell. Any battery engineer will tell you that it’s necessary to leave some percentage of ceiling above the battery, 10% is a rough rule-of-thumb, and over time the battery will expand into that space. Our two-month old unit had no ceiling: the battery and adhesive was 5.2 mm thick, resting in a 5.2 mm deep pocket. There should have been a 0.5 mm ceiling. This is what mechanical engineers call line-to-line — and since it breaks such a basic rule, it must have been intentional. It is even possible that our unit was under pressure when we opened it.

VIA: Instrumental